The effect of upconversion fluorescence properties in red laser pumping Tm3+ ions doped nanocrystals is studied with laser specroscopy. The upconversion efficiency caused by phonon energy is invesgated by changing the matrix and environment temperature of samples. The results show that suitable photon energy can improve the upconversion efficiency. Since the phonon energy depends on the sample temperature, the variation of the temperature can also influence the population rate of 3H4 level in Tm3+ doped low-phonon-energy crystal, resulting in the change of the fluorescence upconversion efficiency.